streambuf.inl

eCos操作系统源码

#ifndef CYGONCE_LIBC_STDIO_STREAMBUF_INL
#define CYGONCE_LIBC_STDIO_STREAMBUF_INL
//===========================================================================
//
//      streambuf.inl
//
//      Internal C library stdio stream buffer inline functions
//
//===========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//===========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    jlarmour
// Contributors: 
// Date:         2000-04-19
// Purpose:     
// Description: 
// Usage:       Do not include this file directly, instead
//              #include <cyg/libc/stdio/streambuf.hxx>
//
//####DESCRIPTIONEND####
//
//===========================================================================

// CONFIGURATION

#include <pkgconf/libc_stdio.h>   // Configuration header

// Include buffered I/O?
#if defined(CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO)


// INCLUDES

#include <cyg/infra/cyg_type.h>          // Common project-wide type definitions
#include <cyg/infra/cyg_ass.h>           // Assertion support
#include <errno.h>                       // Cyg_ErrNo
#include <stdio.h>                       // fpos_t and iobuf defines
#include <stdlib.h>                      // free()
#include <cyg/libc/stdio/streambuf.hxx>  // header for this file, just in case
#include <limits.h>                      // INT_MAX

// FUNCTIONS
    
inline
Cyg_StdioStreamBuffer::Cyg_StdioStreamBuffer( cyg_ucount32 size,
                                              cyg_uint8 *new_buffer ) :
#if defined(CYGSEM_LIBC_STDIO_SETVBUF_MALLOC)
    call_free(false),
    buffer_bottom( NULL ),
    buffer_size(0),
#else
    buffer_bottom( static_buffer ),
    buffer_size(sizeof(static_buffer)),    
#endif    
    buffer_top(NULL),
    current_buffer_position(NULL)
{
    // NB Many of the above members in the initialisation list may seem
    // unnecessary, but it is to ensure a defined state if e.g. the malloc
    // in set_buffer() should fail

    (void)set_buffer(size, new_buffer);
} // Cyg_StdioStreamBuffer constructor


inline
Cyg_StdioStreamBuffer::~Cyg_StdioStreamBuffer()
{
#ifdef CYGSEM_LIBC_STDIO_SETVBUF_MALLOC
    if ((buffer_bottom != NULL) && call_free)
        free( buffer_bottom );
#endif        
} // Cyg_StdioStreamBuffer destructor


inline cyg_ucount32
Cyg_StdioStreamBuffer::get_buffer_space_used( void )
{
    return (buffer_top - current_buffer_position);
} // get_buffer_space_used()


inline cyg_count32
Cyg_StdioStreamBuffer::get_buffer_size( void )
{
#ifdef CYGSEM_LIBC_STDIO_DYNAMIC_SETVBUF
    if (buffer_bottom==NULL)
        return -1;
#endif
    return buffer_size;
} // get_buffer_size()        


inline cyg_ucount32
Cyg_StdioStreamBuffer::get_buffer_addr_to_read( cyg_uint8 **buffer )
{
    *buffer = current_buffer_position;
    
    return (buffer_top - current_buffer_position);
} // get_buffer_addr_to_read()

inline void
Cyg_StdioStreamBuffer::set_bytes_read( cyg_ucount32 bytes )
{
    cyg_uint8 *buffer_max = &buffer_bottom[ get_buffer_size() ];

    current_buffer_position += bytes;

    // INT_MAX is used by some callers to mean infinite.
    CYG_ASSERT( (current_buffer_position <= buffer_top)
                || (get_buffer_size() == INT_MAX),
                "read too many bytes from buffer" );

    if (current_buffer_position == buffer_max)
        current_buffer_position = buffer_top = &buffer_bottom[0];
    
} // set_bytes_read()


inline cyg_ucount32
Cyg_StdioStreamBuffer::get_buffer_addr_to_write( cyg_uint8 **buffer )
{
    cyg_uint8 *buffer_max = &buffer_bottom[ get_buffer_size() ];
    
    *buffer = buffer_top;
    
    return (buffer_max - buffer_top);
} // get_buffer_addr_to_write()


inline void
Cyg_StdioStreamBuffer::set_bytes_written( cyg_ucount32 bytes )
{
    buffer_top += bytes;

    // INT_MAX is used by some callers to mean infinite.
    CYG_ASSERT( (buffer_top <= &buffer_bottom[ get_buffer_size() ])
                || (get_buffer_size() == INT_MAX),
                "wrote too many bytes into buffer" );
} // set_bytes_written()


inline void
Cyg_StdioStreamBuffer::drain_buffer( void )
{
    buffer_top = current_buffer_position = &buffer_bottom[0];
} // drain_buffer()

#endif // if defined(CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO)

#endif // CYGONCE_LIBC_STDIO_STREAMBUF_INL multiple inclusion protection

// EOF streambuf.inl